package com.jlu.yygh.filter;

import com.alibaba.fastjson.JSONObject;
import com.jlu.yygh.common.helper.JwtHelper;
import com.jlu.yygh.common.result.Result;
import com.jlu.yygh.common.result.ResultCodeEnum;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.util.AntPathMatcher;
import org.springframework.util.StringUtils;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.nio.charset.StandardCharsets;
import java.util.List;

/**
 * 全局Filter，统一处理会员登录与外部不允许访问的服务
 */
@Component
public class AuthGlobalFilter implements GlobalFilter, Ordered {

  private AntPathMatcher antPathMatcher = new AntPathMatcher();

  @Override
  public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
    ServerHttpRequest request = exchange.getRequest();
    String path = request.getURI().getPath();
    System.out.println("==="+path);

    //内部服务接口，不允许外部访问
    if(antPathMatcher.match("/**/inner/**", path)) {
      ServerHttpResponse response = exchange.getResponse();
      return out(response, ResultCodeEnum.PERMISSION);
    }

    //api接口，异步请求，校验用户必须登录
    if(antPathMatcher.match("/api/**/auth/**", path)) {
      Long userId = this.getUserId(request);
      if(StringUtils.isEmpty(userId)) {
        ServerHttpResponse response = exchange.getResponse();
        return out(response, ResultCodeEnum.LOGIN_AUTH);
      }
    }
    return chain.filter(exchange);
  }

  @Override
  public int getOrder() {
    return 0;
  }

  /**
   * api接口鉴权失败返回数据
   * @param response
   * @return
   */
  private Mono<Void> out(ServerHttpResponse response, ResultCodeEnum resultCodeEnum) {
    Result result = Result.build(null, resultCodeEnum);
    byte[] bits = JSONObject.toJSONString(result).getBytes(StandardCharsets.UTF_8);
    DataBuffer buffer = response.bufferFactory().wrap(bits);
    //指定编码，否则在浏览器中会中文乱码
    response.getHeaders().add("Content-Type", "application/json;charset=UTF-8");
    return response.writeWith(Mono.just(buffer));
  }

  /**
   * 获取当前登录用户id
   * @param request
   * @return
   */
  private Long getUserId(ServerHttpRequest request) {
    String token = "";
    List<String> tokenList = request.getHeaders().get("token");
    if(null  != tokenList) {
      token = tokenList.get(0);
    }
    if(!StringUtils.isEmpty(token)) {
      return JwtHelper.getUserId(token);
    }
    return null;
  }
}
